Comparison of PPP, PPP-AR and PPP-RTK

PPP (Precision Single-Point Positioning), PPP-AR (Precision Single-Point Positioning Ambiguity Resolution) and PPP-RTK (Real-Time Kinematic Precision Single-Point Positioning) are the three key technologies in GNSS high-precision positioning, and they have their own characteristics and applicable scenarios. The following is a comparative analysis of these three techniques:

 1. PPP 
 Principle: Use globally distributed reference station data to generate precision orbit and clock difference products, and realize high-precision positioning through a single receiver.
 Advantage: No local reference station is required, suitable for environments with large range and no regional reference station support;
 Positioning accuracy can reach centimeter to decimeter level (higher in static mode).
 Disadvantages: longer convergence time (usually takes tens of minutes to hours); more sensitive to atmospheric delay (ionosphere and troposphere) errors;
 Inability to directly fix the carrier phase ambiguity.
 Application scenarios: global geodesy, crustal deformation monitoring, etc.; scenarios that require long-time observation and do not require high real-time performance.

2. PPP-AR
 Improvement points relative to PPP technology: Fuzzy degree fixing technology is introduced on the basis of PPP, which solves the problem of integer characterization of carrier phase fuzzy degree.
 Advantages: Convergence time is significantly shortened (compared with traditional PPP); positioning accuracy is further improved to millimeter level; more suitable for dynamic application scenarios.
 Disadvantages: higher requirements for satellite orbit, clock difference and atmospheric correction model; increased computational complexity, requiring more powerful processing capabilities.
 Application scenarios: dynamic high-precision positioning, such as UAV navigation, autonomous driving, etc.; high-precision real-time applications, such as seismic monitoring, structural health monitoring.

3. PPP-RTK 
 Principle: Combining the advantages of PPP technology and RTK, realizing real-time high-precision positioning by providing enhanced information (such as regional atmospheric correction, satellite deviation, etc.) through a network of regional reference stations.
 Advantages: very short convergence time (a few seconds to a few minutes); positioning accuracy comparable to RTK (centimeter or even millimeter level); larger coverage than traditional RTK (hundreds of kilometers).
 Disadvantages: need to rely on the regional reference station network, higher construction and maintenance costs; data transmission links may be limited by communication conditions.
 Application scenarios: real-time high-precision positioning needs, such as precision agriculture, intelligent transportation, unmanned driving; regional high-precision positioning services.

Wisdom Beidou’s new generation of agricultural machinery automated steering system can be equipped with optional star base board card with PPP-AR technology, star service covers most of the world, no network can also realize centimeter-level high-precision positioning, operating speed interval 0.1-25km/h, articulation line accuracy ± 2.5cm.